ISO 9912-3:2013

INTERNATIONAL ISO
STANDARD 9912-3
Second edition
2013-10-01
Agricultural irrigation equipment —
Filters for microirrigation —
Part 3:
Automatic flushing strainer-type
filters and disc filters
Matériel agricole d’irrigation — Filtres pour micro-irrigation —
Partie 3: Filtres à tamis et filtres à disque auto-nettoyants
Reference number
ISO 9912-3:2013(E)
©
ISO 2013

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ISO 9912-3:2013(E)

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© ISO 2013
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ISO 9912-3:2013(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Marking . 2
5 General requirements . 2
6 Design and construction requirements . 2
6.1 Mandatory requirements . 2
6.2 Optional features . 4
7 Performance tests . 4
7.1 General . 4
7.2 Volume of flushing water and duration of flushing . 5
7.3 Operation of the flushing control mechanism . 5
7.4 Operation of the protective mechanism . 6
8 Performance tests after long term simulated use . 7
8.1 Multiple flushing cycles procedure‎ . 7
8.2 Tests following the multiple flushing cycles . 7
9 Information to be supplied by the filter manufacturer . 8
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ISO 9912-3:2013(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
The committee responsible for this document is ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 18, Irrigation and drainage equipment and systems.
This second edition cancels and replaces the first edition (ISO 9912-3:1992), which has been
technically revised.
ISO 9912 consists of the following parts, under the general title Agricultural irrigation equipment —
Filters for microirrigation:
— Part 1: Terms, definitions and classification
— Part 2: Strainer-type filters and disc filters
— Part 3: Automatic flushing strainer-type filters and disc filters
A fourth part on granulated media filters is planned.
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INTERNATIONAL STANDARD ISO 9912-3:2013(E)
Agricultural irrigation equipment — Filters for
microirrigation —
Part 3:
Automatic flushing strainer-type filters and disc filters
1 Scope
This part of ISO 9912 specifies general construction requirements and test methods for automatic
flushing strainer-type filters and disc filters (hereinafter called “filters”) intended for operation in
agricultural irrigation systems.
It does not cover the aspects of filtration ability, efficiency and capacity (like quality of filtered water or
time of operation before filter becomes entirely clogged).
NOTE 1 The parameters of filtration ability, efficiency and capacity, their definitions and their test methods are
to be included in a separate ISO International Standard or Technical Report. The test methods will be described
in that document, using water as defined by the client, to characterize the filter properties during operation
with this water, or with water defined by the tester or the client, for comparison between various filters under
identical operating conditions.
NOTE 2 ISO 9912-2 covers strainer-type filters and disc filters in general (see Clause 5).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 9912-1, Agricultural irrigation equipment — Filters for micro-irrigation — Part 1: Terms, definitions
and classification
1)
ISO 9912-2:— , Agricultural irrigation equipment — Filters for microirrigation — Part 2: Strainer-type
filters and disc filters
3 Terms and definitions
For the purposes of this part of ISO 9912, the following terms and definitions apply, together with the
relevant definitions in ISO 9912-1 and ISO 9912-2.
3.1
automatic flushing filter
filter in which both the initiation and the termination of discrete flushing cycles are activated
automatically
3.2
duration of automatic flushing cycle
period of time during which water and clogging material are flushed out
1) To be published. (Revision of ISO 9912-2:1992)
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ISO 9912-3:2013(E)

3.3
flushing control mechanism
mechanism which initiates and terminates the flushing action of a filter
3.4
flushing valve
valve through which flushing water is discharged from a filter
3.5
minimum working pressure
lowest pressure immediately upstream from a filter that is recommended by the manufacturer to ensure
proper operation
3.6
minimum filtering pressure
lowest working pressure immediately upstream from a filter, declared by the manufacturer, which
ensures the proper functioning of a filter while in the filtering mode
3.7
minimum flushing pressure
lowest working pressure immediately upstream from a filter, declared by the manufacturer, which
ensures proper flushing while in the flushing mode
3.8
prefiltration element
part of a filter intended to protect the filter element and cleaning mechanism by collecting especially
large particles of the clogging material prior to their reaching the main filter element
3.9
protective mechanism
mechanism that prevents repeated flushings of a filter caused either by mechanical failure in the flushing
control mechanism or by some other fault
3.10
volume of flushing water
volume of water flushed from a filter during one flushing cycle
4 Marking
Each filter shall bear all the markings specified in ISO 9912-2:—, Clause 4.
The filter markings shall also include a calibrated permanent scale which shows the individual setting
positions, where these exist, for the various options of adjustment of the automatic flushing cycle.
5 General requirements
All the requirements that are included in ISO 9912-2 apply to automatic flushing filters, in addition to
the specific requirements and tests that are included in this part of ISO 9912.
6 Design and construction requirements
6.1 Mandatory requirements
Models of typical automatic flushing filters are shown in Figure 1 and Figure 2.
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ISO 9912-3:2013(E)

Key
1 inlet 5 filter element
2 outlet 6 flushing valve
3 filter housing 7 flushing control mechanism
4 filter housing cover 8 prefilter
Figure 1 — Typical structure of an automatic flushing strainer-type filter
Key
1 inlet
2 outlet
3 filter housing
4 disc elements
Figure 2 — Typical structure of an automatic flushing disc filter
The construction of an automatic self-cleaning filter shall comply with the following requirements.
a) The flushing control system shall be a part of the filter assembly and shall be supplied by the
manufacturer together with the filter, or shall be a part produced by the filter manufacturer and
supplied according to special demand of the customer. Alternatively, the flushing control system
may be manufactured by a third party, provided that it is approved by the filter manufacturer and
is included in the information supplied by the manufacturer (see Clause 9).
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ISO 9912-3:2013(E)

b) The construction of the filter shall allow manual actuation of automatic flushing in the event of
failure of the automatic flushing control mechanism.
c) The flushing control mechanism shall allow manual flushing at any time, irrespective of the
conditions that apply to automatic flushing.
d) The construction of the filter housing shall permit
...